Electric circuit breaker



June 22, 1937. J. BIERMANNS 2,084,885

ELECTRIC CIRCUIT BREAKER Filed Nov. 6, 1936 3 Sheets-Sheet 2 I Inventor: Josef Biermomns,

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June 22, 1937. J BIERM N 2,084,885

ELECTRIC CIRCUIT BREAKER Filed Nov. 6, 1936 3 Sheets-Sheet 5 Fig. I z.

I// J k'-79 I /77 76 i 78 {L t Inventor: JOSEF Bievmomns,

is Atborheg.

' Patented June 22, 1931 2 4, 5,

UNITED STATES PATENT OFFICE 2,084,885 ELECTRIC omcurr BREAKER Josef Biermanns, BerIin-Johannisthal, Germany,

assignor to General Electric Company, a corporation of New York Application November 6, 1936, Serial No. 109,561 In Germany November 28, 1935 9 Claims. (Cl. 200-448) This invention relates to electric circuit breakrespect thereto by means of a pivoted arm 3. ers, more particularly to those of the air-break The relatively fixed structure I comprises a contype for high voltage circuits employing a prestact member t in the form of a rod provided sure jet of suitable arc extinguishing fluid, such with an arcing tip composed of suitable heat 5 as air, water, water vapor, or carbon dioxide, for resisting metal, such as tungsten, for example. 5

example, as the interrupting medium. The contact d is movable longitudinally of and A principal object of the invention is the prowithin a fluid passage 6 which is formed by an vision of an improved high voltage circuit breaker insulating nozzle-shaped member 1. The throat of the aforesaid type which is eificient in operaor restricted part of the nozzle at 8 is located tion and simple in construction as compared with adjacent the point of contact separation. 10

conventional types of gas blast circuit breakers. For the purpose of initially operating the con- In accordance with the invention, in a pretact 4 a piston 9 connected to the contact is opferred embodiment thereof at least one of the erable within a cylinder Ill against the bias of coacting electrodes is arranged to move within a a spring ii. A source of fluid pressure (not 5 nozzle-like fluid passage, generally in a direction S own) s ad pt to be in Communication W t opposite to that of the fluid flow, and the fluid the conduit at l2 for supplyi g fl d under D guiding means during the initial separation of sure to the'passage 6. The coacting contact l3 the electrodes or contacts forms with the coactof the movable structure 2, which may if desired ing relatively movable structure a high pressure he in t e form of a S cket Conta t, e e t chamber which is subsequently opened to release o ta t in't e cl s d Circuit p s adjacent 20 the fluid blast and effect interruption of the arc. the throat ii of the gas passage.

There is disclosed and claimed generally in my Accordingly, W u d under p e s dco-pending application, Serial No. 110,398, filed t d o the passage ii o the P p Of inter- November 11, 1936, for Electric circuit breaker r pt n t e C uit at the contacts 4 and I3, t e

2 a fluid blast electric circuit breaker basically of fluid pressure first causes retraction of the con- 5 the present character. tact l against the bias of spring H, the move- My invention will be more fully set forth in the ment of the gas or fluid being indicated by the following description referring to the accompanydirectional arrows. It will be apparent that the ing drawings, and the features of novelty which contact d may be mechanically operated if so characterize my invention will be pointed out desired. 30 with particularity in the claims annexed to and For the purpose of preventing corona and efforming a part of this specification. fecting a more homogeneous distribution of the Referring to the drawings Fig. 1 is an elevaelectric field, as well as guiding the exhaust fluid,

tional view, partly in section, of an electric cirthe insulating member 1 is provided near the cuit breaker in the open-circuit position embodythroat thereof with a metallic hood or shield l t, ing the present invention; Fig. 2 is a similar the hood being convex as illustrated with respect View, partly in section, showing another form of to the point of contact and provided with a centhe invention in an intermediate position, Figs. tral aperture which merges with the exhaust 4O 3 to 7 inclusive are diagrammatic illustrations opening of the passage 6. The movable strucof circuit breaker arrangements to which the ture 2 is similarly provided with a hood l5, the present invention is readily applicable, Figs. 8 two hoods being convex with respect to each and 9 are plan and elevational views, respecother and in substantial engagement to close the tively, of a rotary disconnecting switch to which exhaust opening in the passage 6 in the closed the present invention is applied; Figs. 10 and 11 circuit position. r are similar views of a double rotary disconnecting The circuit opening operation is initiated by switch, and Figs. 12 and 13 are likewise similar admitting fluid under pressure to the passage 6. views of a high voltage power disconnecting As previously pointed out the contact 4 is thereswitch to which the present invention is applied. by retracted from the coacting contact 13 caus- 5 Referring more particularly to Fig. 1, there is ing initial separation of the contacts. The hoods illustrated relatively movable electrode or contact id and i5, however, are still in engagement so structures generally indicated at l and 2 in the that the nozzle exhaust is closed and a high presopen-circuit position thereof. In the present insure arc chamber thereat is formed by the coactstance the electrode structure i may be relaing structure. The arc is therefore not only subtively fixed and the structure 2 movable with jected to the quenching effect of a high pressure 55 atmosphere but the arc energy is also comparatively low since the arc is not appreciably lengthened. After initial contact separation the hood I5 moves away from the hood M with the result that an effective gas blast at the nozzle throat 8 causes interruption of the arc. This stage of the operation is indicated by Fig. 1.

The movable electrode structure 2 continues to move away from the electrode structure I so that there is adequate isolating distance between the electrodes in the open-circuit position. The gas blast is discontinued immediately upon circuit interruption and the spring I I automatically returns the contact 4 to its original position. The circuit closing operation is effected by relative return movement of the contact structures I and 2, the contacts engaging adjacent the throat of the gas passage, 1. e., near the point of engagement of the hoods.

During the circuit opening operation the contact 4 reaches the zone behind the throat opening 8 of the nozzle, in which a high pressure as well as high velocity of the arc extinguishing medium, prevails. Thus, the contact is moved against the flow of the fluid medium behind the narrowest point of the gas passage.

As previously pointed out, the hoods l4 and I5 are stationary during the initial application of the fluid medium so as to define a high pressure chamber for the arc. After the contacts have separated a predetermined distance the movable structure 2 including the hood I5 can be moved away from the structure I so that an adequate insulating gap is established in the free air space.

The specific construction of the insulating member forming the gas passage and the hood may obviously be varied without departing from the spirit of the invention. For example, the member I and the hood I l may consist of a single metal piece suitably covered with insulating material.

It shall be understood that the coacting contact structure 2 of Fig. 1 may be identical with that of the electrode structure 6, in which case a jet of fluid is directed on each of the contacts.

In Fig. 2 there is illustrated another form of the invention wherein the coacting electrode structures are substantially identical. In contradistinction to the form of construction shown by Fig. 1, the electrodes or contacts l6 and H are arranged as comparatively fixed members and the corresponding hoods I8 and I9are displaceable.

The contacts are guided for longitudinal movement with respect to the hood members at 9. The hoods are normally biased into engagement with each other by springs 20- which bear on the inner sides of the hoods against flanged members 2| forming a portion of the gas conduit. The members 2| are operable with the contacts. As in the previous case the insulating members 22 and 23 are united to the hoods I8 and I9 respectively to form gas passages having restricted throat portions 22' and 23 respectively.

In the closed circuit position the tip of each contact is substantially even with the outer surface of the hoods as illustrated by dotted lines.-

In accordance with the circuit opening operation the oppositely located contacts are withdrawn into the enlarged parts of the gas passages behind the throat or restricted part of the nozzle by the relative movement of the hoods with respect to the contacts under the action of the springs 20. That is, the contacts are suitably released by means (not shown) so that the springs ace gees 2B acting on the members 2I cause the initial contact separation.

During the first part of this relative movement, however, no separation of the hoods I8 and I9 takes place. Fig. 2 corresponds to this phase of the opening operation. Although the contacts are separated the hoods still remain in engagement so that they define a limited chamber of high pressure. However, after untensioning of the springs 20 the mutual separation of the hoods takes place by suitable means whereby a longitudinal and transversal flow of the arc extinguishing fluid takes place between the convex surfaces of the hoods in a radial direction as indicated by the directional arrows 24. This fluid blast aids the extinguishing effect of the high pressure fluid. By means of suitable devices, for example, latching arrangements, not represented in the drawings, the mutual separation of the hoods can be caused to take place suddenly.

The subject matter of this invention can be used with advantage in arrangements wherein the contacts as well as the hoods are movable, and also in various forms of construction of disconnecting or power switches. In this case the arrangement would be made in'a suitable manner, so that the flow of the interrupting fluid substantially coincides with the axis of the arc.

Thus, for example, in Fig. 3 a rotary disconnecting switch is diagrammatically represented wherein double switch arms 25 and 26 are arranged on a pivotally mounted supporting insulator 21. Each of the switch arms 25 and 26 are movable in common and have an extension disposed at an angle thereto, and an electrode perpendicular to the axis of the switch element.

The electrodes are arranged as above described in nozzle-shaped fluid passages for guiding the arc extinguishing medium to the point of interruption, and the gas passages terminate in hoods which are supported by the fixed supporting insulators 28 and 29.

Fig. 4 represents diagrammatically a construction of a disconnecting switch wherein the electrodes are arranged at an angle to the separately movable switch arms 30 and 3 I. The switch arms are mounted on outer rotatable supporting insulators 32 and 33 so as to be movable relative to each other. In this case two rotatable arms are employed to form but a single break.

In Fig. 5 there is indicated an arrangement wherein a double disconnecting switch comprising two rotatable members 34 and 35 are mounted on the two inner rotatable supporting insulators 3B and 31. The switches are shown in the open-circuit position and are closed by counterclockwise rotation of both members 34 and 35 as indicated.

Fig. 6 indicates a type of disconnecting switch having switch arms 38, 39 movable with respect to each other through an arc. In this case the fluid medium is also directed, as indicated by the arrows, so as to be in the direction of the separating movement of the contacts.

Fig. '7 indicates another form wherein a double arm 40 is rotatable about the central supporting insulator 4|. The arrangement of the fixed and movable switching elements in this case is determined so that the initial separating movement occurs in the direction of flow of the gas blast, or opposite thereto, as indicated by the gas flow directional arrows.

The compressed gas can in these cases be directed from the supply source to the electrode structure through the fixed or movable insu lators; for example, the gas passages can be formed in part by the rotary insulators, or if desired, by both the fixed and movable insulators.

Figs. 8 and 9 illustrate an arrangement wherein a power disconnecting switch is constructed as a rotary disconnecting switch having at least one rotatable switch arm. The switch arms are preferably hollow and of such size thatthe specific switching apparatus above described and the pressure gas conduit are contained within the switch arm.

Referring more particularly to the construction shown, the power disconnecting device comprises a pair of pin-type insulators 42 and 43 which are rotatably mounted on a base plate 44. The rotatable insulators carry the switch arms 45 and 46 which terminate in the corona shields or hoods 41 and 48 respectively. The corona shields enclose the specific contact structure which is not shown. The breaker terminals are connected to the main circuit at 49 and 50.

The actuating means for the insulators 42 and 43 comprise the driving devices indicated at and 52 which are operatively connected to a suitable source of gas pressure through the conduits 53 and 5 3 respectively. The driving devices, the details of which are immaterial so far as the present invention is concerned, coact with the ring gears 55 and 56 carried by the lower ends of the insulators. Admission of gas under pressure through the conduits 53 and M causes rotation of the insulators and the switch arms to positions indicated in dotted lines in Fig. 9.

As above pointed out the rotatable switch arms 15 and 25 are constructed as hollow members and are so dimensioned that they provide accommodation for both the switch contact structure and the application of pressure gas thereto for interruption of the circuit. The gas conduits 5'! and 58 extending axially of the insulators 42 and A3 indicate the application of gas under pressure from a suitable source to the switch contacts at ill and 58.

In one arrangement, for example, one of the contacts can be fixed and the other mounted with respect thereto for rotational movement, the gas blast being directed from the rotating arm. How ever, in the preferred arrangement both contacts are mounted on rotatable arms and the pressure gas for interrupting the circuit is directed from both arms. In all cases it is advantageous to arrange the corona shields 4'l and 48 with respect to the switch contacts as flow nozzles of the pressure gas switch.

The method of operation of the rotary disconnecting switch is as follows: In the closed circuit position illustrated by Figs. 8 and 9 the corona shields are in direct engagement and enclose the switch contacts which are also in engagement. When the switch is to be opened pressure gas is first directed through the rotatable arms 45 and 46 and the contact separation is eifected as described in detail in connection with Figs. 1 and 2. Immediately upon separation, or if preferred, with slight delay, gas pressure is applied to the driving mechanism 5| and 52 for causing rotation of the insulators and movement of the switch arms to the dotted line positions illustrated in Fig. 9. As the corona shields separate, the arc is interrupted by the gas blast in the manner above described, and in the fully open circuit position an air gap of considerable length is interposed between the contacts.

Figs. and 11 show an application of the invention to a double rotary disconnecting switch.

In this case the rotatable switch arms 59 and 60, which are mounted'on a base plate 6| by means of rotary insulators 62 and 63, are hollow as in the previous case for containing the switch interrupting apparatus. The switch arms are provided at one end with the corona shields 64 and 65 which enclose respectively coacting contacts and at their opposite ends switch blades 66 and 61 having contacts 68 and 69 respectively. These contacts coact with stationary contacts 10 and 1| which are mounted on fixed pin-type insulators 12 and 13 respectively.

Figs. 10 and 11 illustrate in solid lines the opencircuit position' of the switch, the closed position being illustrated by the dotted line position shown in Fig. 11. The operation is substantially the same as that above described except that the arms in the open-circuit position form three air gaps for isolating the switch. The disconnecting contacts 68 and 69 are preferably of the sliding type so that the circuit interruptionat M and 65 is completed before the contacts 68 and 69 separate.

In this arrangement provision may be readily made for removing the switch for inspection or repair after the opening operation. As shown by Fig. 10 the base plate may be provided with rollers ti for rolling out the insulators t2 and 63 which support the switch structure.

It will be apparent that the switch blades $6 and 6'5 can also be constructed similarly to the arms 59 and Gil if desired for applying the gas blast to all three points of interruption.

Figs. 12 and 13 illustrate a high voltage power disconnecting switch wherein a pair of switch arms of the character above described are rotatably mounted on insulators which are inclined at an angle so as to reduce the over-all height of the switch structure.

More specifically the rotatable insulators l4 and 55 are mounted on a base structure it and are provided with switch arms Ill! and It. The

switch arms coact to form a single break at the static shields or hoods "l9 and 86 respectively. As in the previous case the shields surround the switch contact structure which is not shown.

I At the lower ends of the insulators M and K5 are driving devices 8i and 82 respectively which include bevel gears 83 and 84 arranged to coact with the ring gears 85 and 86 secured to the insulators. As illustrated the insulators are mounted on inclined bases 81 and 88, so that the longitudinal axes of the insulators are inclined towards each other at the upper portions.

Asource of compressed air, generally indicated by a conduit 89, is connected through the pipes 90 and 9! to the housings at 8! and 82. The compressed air is directed to the electrodes at 19 and 80 through the insulators l4 and and through the hollow switch arms 11 and 78, the interruption of the-circuit being in the manner previously described. The compressed air is first directed to the contact structure causing separation of the contacts, and the insulators are thereupon rotated to effect separation of the static shields. The compressed gas emitting from the switch arms thereupon causes interruption of arcing and the continued opening movement of the arms to the dotted line position shown by Fig. 12 results in an insulating air gap of sufficient length. The main circuit conductors are connected to the breaker terminals at 92 and 93.

It should be understood that my invention is not limited to specific details of construction and arrangement thereof herein illustrated, and that changesand modifications may occur to one skilled in the art without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electric circuit breaker of the fluid blast type comprising relatively movable contact structure, means coacting with said structure for directing a fluid under pressure to the point of separation thereof in accordance with the circuit opening operation, and means operatively related to said contact structure substantially enclosing the same during initial separation thereof, said enclosing means arranged to release a blast of said fluid to interrupt the arc subsequent to separation of said contact structure.

2. An electric circuit breaker comprising relatively movable contact structure, fluid passage means related to at least one portion of said contact structure for directing a fluid under pressure to the point of contact separation in accordance with the circuit opening operation, and relatively movable means operatively related to said contact structure for closing said passage during initial separation of said contact structure for defining a high pressure are chamber, said enclosing means separable after initial separation of said contact structure to open said fluid passage.

3. An electric circuit breaker comprising relatively movable contact structure, fluid passage means for directing a fluid under pressure to the point of separation of said contact structure, a plurality of hood members operatively related to said contact structure and arranged to close said fluid passage adjacent the point of contact engagement in the closed circuit position, at least one of said hood members having an opening in registry with said fluid passage, and means for effecting separation of said contact structure within said fluid passage, said hood members initially remaining in engagement to close said passage and subsequently opening after predetermined separation of said contact structure for releasing the fluid blast.

4. An electric circuit breaker comprising a pair of contacts, means forming a fluid passage having a restricted exhaust position, one of said contacts operable within said passage and away from said restricted portion in opposition to fluid flow in the circuit opening movement and the other of said contacts operable exteriorly of said restricted portion and in the direction of said fluid flow, and a pair of hood members operatively related to said contacts respectively, said hood members having coacting surfaces generally convex with respect to each other and arranged to close said fluid passage in the closed circuit position of said contacts, said hood members arranged to separate and open said passage upon separation of said contacts.

5. An electric circuit breaker comprising relatively movable contact structure, a pair of mutually convex members adapted to be in engagement along the central axes thereof, said point of engagement being adjacent the point of separation of said contact structure and in registry with central fluid apertures in said members, fluid passage means for directing a fluid under pressure from the concave sides of said members towards the point of contact separation, said members closing said fluid flow passages initially and adapted to separate subsequent to separation of said contact structure for releasing a gas blast from said passages through the are formed thereat, said blast exhausting radially between said convex members.

6. An electric circuit breaker comprising a pair of contacts, a hood member associated with each of said contacts, said hood members having opposing mutually convex surfaces arranged to be in engagement in the closed circuit position of said contacts adjacent the point of contact engagement, said contacts being relatively movable with respect to said hood members, means for directing a fluid under pressure from the concave side of at least one of said hood members to the point of contact separation upon opening of the circuit, said hood members subsequently separating to release a fluid blast through the are at said point of separation radially between the said convex surfaces.

'7. An electric circuit breaker comprising a pair of relatively movable contacts, fluid passage means having a restricted exhaust portion within which one'of said contacts is operable, means for connecting said passage to a source of fluid pressure, fluid pressure actuated means connected to said contact for withdrawing the same from said restricted portion when fluid is admitted to said passage, the other of said contacts being operable exteriorly of said passage and movable to engage said first named contact adjacent said restricted portion, an electrostatic shield having a central opening in alinement with said passage, and a second electrostatic shield movable with said coacting contact, said shields having opposing mutually convex surfaces normally coacting in the closed circuit position to close said fluid passage, admission of fluid under pressure to said passage causing separation of said contacts prior to separation of said shields.

8. An electric circuit breaker comprising a pair of relatively movable contacts, means defining a fluid passage for each of said contacts from a source of pressure to the point of contact separation, said passages being in substantial alinement so that the fluid flow from one passage opposes that from the other, a hoodlike member disposed at the exhaust portion of each of said fluid passages and having a central aperture in alinement with said passage, the opposing faces of said members being generally mutually convex so as to form an annular diverging passage extending radially from the central axw of said members, and means for effecting separation of said contacts adjacent the exhaust openings of said passages in accordance with admission of fluid under pressure to said passages, said hoodlike members remaining in substantial engagement to close the exhaust openings of said passages subsequent to separation of said contacts.

9. An electric circuit breaker forming a combined power interrupter and air-break disconnecting switch comprising a pair of substantially vertically positioned insulators, said insulators being mounted for rotational movement with respect to the longitudinal axes thereof, a switch arm carried by each of said insulators, coacting contact structure including a pair of hoodlike members having opposingmutually' convex surfaces carried by said switch arms, and means for directing fluid under pressure through said insulators and switch arms to the point of separation of said contact structure, said fluid exhausting radially from the point of contact separation and between said convex surfaces.

J OSEF BIERMANNS. 

